실리콘 이온주입 SiO₂층의 나노결정으로 부터의 광루미네센스

김광희,오항석,장태수,권영규,이용현,Kim, Kwang-Hee,Oh, Hang-Seok,Jang, Tae-Su,Kwon, Young-Kyu,Lee, Yong-Hyun 한국센서학회 2002 센서학회지 Vol.11 No.3

실리콘 기판 위에 형성한 열산화막에 실리콘이온을 주입하고 열처리를 수행한 후, 광루미네센스(photoluminescence:PL) 스펙트럼을 조사하였다. 실리콘 이온도즈의 변화와 열처리 온도의 변화에 따른 PL스펙트럼을 조사하고, 이를 TEM과 XRD 데이터와 비교하여 분석한 결과, 광루미네센스 특성은 산화막내의 실리콘 나노결정으로부터 기인함을 알 수 있었다. 또 산화막을 1분 간격으로 습식 식각하면서 매 식각 시마다 PL스펙트럼을 관측하여 그 변화를 조사하였다. 이러한 실험을 통하여 산화막내에 분포하고 있는 실리콘 나노결정의 크기와 그 수가 PL피크 파장과 강도에 직접적으로 영향을 줌을 알 수 있었다. Photoluminescence(PL) properties of $Si^+$-implanted $SiO_2$ film, which was thermally grown on c-Si substrate, is reported. We have compared room temperature photoluminescence (PL) spectra of the samples which was made in several kinds of implantation, subsequent annealing and $SiO_2$ film thickness. XRD data was correlated with the PL spectra. Silicon nanocrystals in $SiO_2$ film is considered as the origin of the photoluminescence. PL spectra was investigated after wet etching of the $SiO_2$ film by using BOE (Buffered Oxide Etchant) at every one minute. PL peak wavelength was varied as the etching is proceeded. These results indicate that the quantity and the distribution of dominant size of Si nanocrystals in $SiO_2$ film seem to have a direct effect on PL spectrum.

확률적 표본추출 방법을 이용한 집단 약동학 모형의 추정과 검증에 관한 고찰

김광희,윤정화,이은경,Kim, Kwang-Hee,Yoon, Jeong-Hwa,Lee, Eun-Kyung 한국통계학회 2015 응용통계연구 Vol.28 No.2

본 논문에서는 집단 약동/약력학 모형 추정을 위한 다양한 추정방법들을 이론적으로 비교, 분석하였다. 특히 확률적 표본을 이용한 방법들인 IMP, IMPMAP, SAEM 방법과 베이지안 방법의 이론적 배경과 이들의 성능을 자세히 살펴보고, 기존의 선형근사를 이용한 FO, FOCE 등의 방법과 비교 분석하였다. 확률적 표본을 이용한 추정방법들이 추정에 많은 시간이 소요된다는 문제점을 개선하기 위하여 좀 더 좋은 초기치를 찾는 방안으로 상대적으로 짧은 시간에 정확한 추정치를 계산해주는 ITS 방법을 이용하였다. This study is about estimation methods for the population pharmacokinetic and pharmacodymic model. This is a nonlinear mixed effect model, and it is difficult to find estimates of parameters because of nonlinearity. In this study, we examined theoretical background of various estimation methods provided by NONMEM, which is the most widely used software in the pharmacometrics area. We focused on estimation methods using a stochastic sampling approach - IMP, IMPMAP, SAEM and BAYES. The SAEM method showed the best performance among methods, and IMPMAP and BAYES methods showed slightly less performance than SAEM. The major obstacle to a stochastic sampling approach is the running time to find solution. We propose new approach to find more precise initial values using an ITS method to shorten the running time.

A study on the grinding characteristics of the workpiece using the laminated grinding wheel in the cylindrical grinding process

김광희,이은종,김강,Kim, Kwang-Hee,Lee, Ewn-Jong,Kim, Kang The Korean Society of Manufacturing Technology Eng 2000 한국공작기계학회지 Vol.9 No.5

To get smoother ground surface, it is required to replace the grinding wheel with a finer-grit wheel. When the operator replaces the grinding wheel, the balancing and dressing of the wheel surface are necessary. So this replacement has a lot of problems like inconvenience to operators, delays in the operation time, and ineffectiveness in the production process. Therefore, a laminated grinding wheel, which consists of three layers, is provided. The side layers are coarse grits and the middle layer is made up of fine grits. To show the effectiveness of the laminated grinding wheel, experiments on the surface roughness and the material removal rate were performed respectively. As a result, it was found that the grinding process using a laminated grinding wheel can generate smoother ground surface in shorter time.

지진조기경보를 위한 신속 진앙위치 결정

김광희,석봉출,Kim. Kwang-Hee,Rydelek. Paul A.,Suk. Bong-Chool 한국방재학회 2008 한국방재학회논문집 Vol.8 No.6

경제규모의 증가, 산업화, 도시화 등은 결과적으로 우리국민의 잠재적 지진 위험 증가를 야기하였다. 최근에는 비록 우리나라에서 지진으로 인한 인명과 재산의 손실이 미비했지만, 과거 문헌 기록을 보면 우리나라에서도 대규모 피해를 야기한 지진이 발생한 바 있었으므로, 향후 피해를 유발할 수 있는 지진발생 가능성을 간과할 수는 없다. 현재의 과학기술력으로는 단기 지진 예보가 불가능함을 고려할 때 지진재해 저감을 위하여 취할 수 있는 대비책의 하나로써 지진조기경보체계 확립의 중요성이 점차 증가하고 있다. 지진조기경보체계 확립의 취지는 지진발생 후 강진동이 시작하기 전 수 초 혹은 수십 초의 지진대비시간을 확보하고 미리 계획된 조치를 취함으로써 지진재해를 저감하는 것이다. 본 논문에서는 신속한 지진 발생위치 결정을 위하여 진원 부근 2개의 지진 관측소에서 확보한 초동 도착시간과 주변의 다른 관측소에서는 아직 초동이 관측되지 않았다는 사실을 이용한다. 우리나라 내륙 및 주변해역에서 발생한 주요 지진의 신속한 진앙 위치결정에 이 기술을 적용하였다. 관측소 외부에서 지진이 발생할 경우 이 기술로는 효과적인 지진위치의 결정이 어렵지만, 관측망 내부에서 지진이 발생할 경우 본 기술을 이용하여 지진의 위치를 신속히 결정 할 수 있다. 수도권의 경우 <TEX>$10{\sim}50$</TEX>초의 지진대비시간을 확보할 수 있을 것으로 예상되며, 주어진 시간 내에 사전 준비된 조치를 취함으로써 유사시 지진재해저감에 크게 기여할 것이다. Economic growth, industrialization and urbanization have made society more vulnerable than ever to seismic hazard in Korea. Although Korea has not experienced severe damage due to earthquakes during the last few decades, there is little doubt of the potential for large earthquakes in Korea as documented in the historical literature. As we see no immediate promise of short-term earthquake prediction with current science and technology, earthquake early warning systems attract more and more attention as a practical measure to mitigate damage from earthquakes. Earthquake early warning systems provide a few seconds to tens of seconds of warning time before the onset of strong ground shaking. To achieve rapid earthquake location, we propose to take full advantage of information from existing seismic networks; by using P wave arrival times at two nearest stations from the earthquake hypocenter and also information that P waves have not yet arrived at other stations. Ten earthquakes in the Korean peninsula and its vicinity are selected for the feasibility study. We observed that location results are not reliable when earthquakes occur outside of the seismic network. Earthquakes inside the seismic network, however, can be located very rapidly for the purpose of earthquake early warning. Seoul metropolitan area may secure <TEX>$10{\sim}50$</TEX> seconds of warning time before any strong shaking starts for certain events. Carefully orchestrated actions during the given warning time should be able to reduce hazard and mitigate damages due to potentially disastrous earthquakes.

일부 성인의 구강건강 지식이 구강건강 증진 행위에 미치는 영향

김광희,정윤숙,Kim, Kwang-Hee,Jung, Yun-Sook 한국치위생학회 2021 한국치위생학회지 Vol.21 No.2

Objectives: This study aimed to investigate oral health-related knowledge in adults and to determine the effect of oral health knowledge on correct brushing and use of dental care products. Methods: The subjects of this study were 552 adults who visited dental clinic, and a self-administered questionnaire was administered. Statistical analysis was performed using the t-test, ANOVA, and multiple regression using the SPSS statistics program (ver. 23.0, IBM Co., Chicago, IL, USA). Results: The oral health knowledge level, correct brushing, and dental care product usage scores were found to be positively correlated (r=0.015, 0.016), and both correlation coefficients were statistically significant (p<0.05). Oral health knowledge was found to have a significant effect on correct brushing among oral health promotion behaviors (β=0.116, p=0.006), but it was not found to have a significant effect on the use of dental care products (β=0.053, p=0.214). Conclusions: Oral health promotion behavior is closely related to oral health knowledge, and it is thought that oral health promotion behavior can be improved by raising oral health knowledge levels.

Hydroxyl Ionization and Iodination of Tyrosine Residues in ${\alpha}$-Amylase

김광희,양철학,최명언,Kwang Hee Kim,Chul-hak Yang,Myung-un Choi Korean Chemical Society 1992 대한화학회지 Vol.36 No.4

공구접근 경로가 밀링 가공된 원통 구멍 형상에 미치는 영향

김광희,Kim, Kwang-Hee 한국기계가공학회 2004 한국기계가공학회지 Vol.3 No.4

Because of the development in mold industries, the geometrical form accuracy of the milled surface is getting more and more important. It has been known that the geometrical form accuracy is affected by machine conditions, cutting conditions, tool conditions and tool path and so on. Among them, the tool approaching path causes the change in material removal per tooth at the end of each machining cycle. And, this change generates the geometrical form error around the region where the tool engages the workpiece initially. So, it is impossible to eliminate the geometrical error caused by the tool approaching path. Thus, characteristics of this geometrical error are studied analytically and experimentally to minimize this region.

1995 년에 발병한 토착형 말라리아 26 예에 대한 임상적 고찰

김광희(Kwang Hee Kim),임채승(Chae Seung Lim) 대한내과학회 1997 대한내과학회지 Vol.52 No.5

N/A Objective: In Korea, control activities against the endemic malaria due to Plasmodium vivax had been done in 1960s. It is now widely accepted in Republic of Korea that indigenous malaria stopped its endemicity in the mid-1970s. But a vivax malaria case without history of being abroad was recognized in 1993. In addition to this case, 20 cases of indigenous malaria were detected in 1994. And they were progressively increased to about 80 cases in 19%. We report these recently developed cases. Methods: In a 7-month period between June and December 1995, high fever patient were examined. Patients having a narcotic drug injection or those who had blood transfusion were excluded. Laboratory studies including blood cell count, peripheral blood smear and abdominal sonogaphy were taken. Results: Over 3-month period from July through September 19%, 26 cases of new indigenous malaria were diagnosed. In a blood smear, plasmodium vivax was diagnosed. Conclusion: The twentysix new indigenous malaria cases occured. Because all the detected patients had no history of visiting endemic countries, they were not imported cases. Vivax malaria in the present patients can be contracted by infected mosquitos which came across the militarized zone (DMZ). Officially speaking, DMZ is a 4 km wide between the north and south borders, Hut the width is much narrower in many parts. However, we do not have any information on the malaria situation in the north Korea. In order to evaluate a significance of the recent indigenous malario occurrence, a surveillance system should be operated in these areas.

구강건강정보 이해능력이 인지된 구강건강상태에 미치는 영향

김광희 ( Kwang Hee Kim ),정윤숙 ( Yun Sook Jung ),황태윤 ( Tae Yoon Hwang ),김창윤 ( Chang Yoon Kim ) 대한예방치과·구강보건학회 2019 大韓口腔保健學會誌 Vol.43 No.1

Objectives: This study was conducted to analyze the effect that oral health literacy of adults has on perceived oral health state and to identify the factors that affect perceived oral health status. Methods: A self-administered questionnaire survey was distributed to 554 adults who lived in the Daegu or Gyeongbuk areas and visited dental institutions located in the Daegu area. For adults who were 60 years old or older, direct interviews were conducted. Statistical analysis was performed with t-tests, analysis of variance, and multiple regression using SPSS. Results: Between oral health literacy and perceived oral health status, a significant positive correlation was revealed (r=0.142, P<0.01). A significant positive correlation was revealed between oral health literacy and knowledge (r=0.397, P<0.01). A significant but weakly positive correlation was revealed between oral health knowledge and perceived oral health status (r=0.086, P<0.05). To identify factors affecting perceived oral health status, multiple regression analysis was conducted, and the result showed that oral health literacy was a statistically significant factor (b=0.105, P<0.05). Among general characteristics, age was a statistically significant negatively affecting factor, as it showed a negative relationship with perceived oral health status (β=―0.140, P=0.001, adjusted R²=0.049). Conclusions: When these study results are taken into consideration, oral health literacy is a factor affecting perceived oral health status, and as such, oral health literacy of the research targets should be taken into consideration when implementing oral health education to promote oral health.

주요 소재 · 부품 산업의 대일(對日) 무역 현황과 그 경쟁력에 관한 연구

김광희(Kwang Hee Kim) 한국무역연구원 2015 무역연구 Vol.11 No.3

This study, which was conducted by selecting items in the materials and parts sector that were included in the top 30 Korean imports from Japan based on the import amount, aimed to identify the competitiveness of these import items relative to that of Japan. Results showed the following: First, a chronic deficit with Japan decreased for four consecutive years and dependence on imports from Japan in the materials and parts sector also recorded an all-time low (18.1%) in 2014 from 25.2% and 23.0% in 2010 and 2012, respectively. Second, as of 2014, 'automobile parts' and 'lubricating oil' were the only two items which displayed competitiveness compared to Japan among the 30 items analyzed. All the remaining 28 items were found to have negative competitiveness indices. In addition, 17 items have competitiveness indices of less than -0.60 and hence, competitiveness relative to Japan was assessed to still be vulnerable. Third, as of 2014, Korea still showed import dependence on Japan up to more than 60% among the 30 items for seven items such as 'other optical equipment parts' to 'other basic oil', 'styrene', 'diesel', 'propylene', 'plate glass', 'toluene'. Moreover, 'diesel' and 'propylene' showed dependence on Japanese imports of more than 80% from 2000 to 2014. In particular, dependence on 'propylene' reached a whopping 98.8%, showing that Korea was mostly dependent on Japan for materials and parts.